1. Field of the Invention
The present invention generally relates to the field of computer security. More specifically, the present invention relates to a method and an apparatus that restricts access to data on a computing device based on a posture assessment of the computing device.
2. Related Art
Corporations deal with an ever-increasing amount of sensitive customer data, such as health records, bank account numbers, government identifiers, and financial records. Accidental or malicious leakage of this data can expose a company to damaging publicity, consumer lawsuits, and punitive governmental action. Unfortunately, many employees, who often are not trained in information technology and security issues, often make mistakes that can lead to the leakage of private customer data. For example, in 2006, the unencrypted personal information of almost 200,000 Hewlett-Packard employees was endangered when a laptop was stolen from the financial services company Fidelity. Another troubling example can be seen by the wealth of unencrypted information that is accidentally shared via file-sharing programs by users unaware of the extent of this sharing.
To deal with this problem, a number of companies have been attempting to develop tools that transparently protect sensitive data to minimize the risk of information leakage from accidents or casual theft. For example, in the Virtual Private Networking (VPN) space, companies have been developing systems that restrict a client's ability to access a VPN based on a “posture assessment” (PA) of the client machine. (This technique is also referred to as “network admission control” (NAC), “device verification” (DV), and “trusted network connect” (TNC).)
The PA technique operates generally as follows. Before allowing a client to connect to a network (either over a VPN or via a direct connection), the state of the client is assessed to determine whether it might be a threat to the network. If so, it may be prevented from connecting to the VPN; or, it may be connected to a quarantine network which it can use to patch itself before being allowed to connect to the VPN with full access. Existing PA implementations vary in what is assessed at each endpoint—from a simple determination of whether a client is currently running firewall and up-to-date antivirus software, to detection of the client's level of service packs and software updates, to fine-grained analysis of the versions of all of the software installed on the machine.
Although existing PA and NAC techniques can protect networks from unauthorized accesses, they do nothing to protect sensitive data after it is retrieved from the network. Note that changes in the security-posture of a client can compromise sensitive data on the client. For example, if malicious code, such as a virus, is inadvertently loaded onto the client, the malicious code may be able to access the sensitive data. This problem can be alleviated by ensuring that sensitive data is never stored on the client, and must always be accessed from a secure server. However, this requires the client to be connected to the network whenever the client needs to access sensitive data, which may not be practical for laptops or other portable computing devices, or for clients with unreliable network connections.
Hence, what is needed is a method and an apparatus that protects sensitive data on a client machine.